[HELP] not really an ISSUE but more of a QUESTION #911

if i may, where can i find the HTML file of heimdall's dashboard? I want to edit the home page to add this
<!--OST Widget code start--><div style="text-align:right;"><div style="min-height:360px;"><div style="width:100%;height:0;padding-bottom:50%;position:relative;"><iframe style="border:none;position:absolute;top:0;left:0;width:100%;height:100%;min-height:360px;border:none;overflow:hidden !important;" src="//openspeedtest.com/Get-widget.php"></iframe></div></div>Provided by <a href="https://openspeedtest.com">OpenSpeedtest.com</a></div><!-- OST Widget code end -->

Anyone knows where or if there is another way to do it? Thank you appreciate the help!